1. Field of the Invention
The invention relates to the field of electrophoretic apparatus. More particularly, the invention is a container for storing and transporting an electrophoretic gel medium. In still greater particularity, the invention is a container which supports a backing sheet to which an electrophoretic gel layer is adhesively attached. By way of further characterization, but not by way of limitation thereto, the invention includes a cover and base for securing a portion of the backing sheet therebetween while maintaining an air space surrounding the gel layer.
2. Description of the Related Art
Electrophoresis involves the placing of a sample substance, such as blood serum or urine, in a support medium across which is maintained a direct current electrical potential. Support media characteristically include: paper; agar; agarose; cellulose acetate and polyacrylamide. The electrical potential causes the colloidal particles in the sample substance to migrate toward one or the other electrodes. The amount of migration is determined by the electrical charges on the particles in the sample substance and the magnitude of the imposed electrical potential. Particles with similar properties tend to group into defined areas and thus a determination can be made as to the amount of each class of substance present in the sample. A graph or analog curve of the relative concentrations of particles can provide information as to the relative proportions of each which are contained in the sample substance. These electrophoretograms provide useful information as to blood serum or urine composition which may be used by clinical pathologists or the like.
It is important to the electrophoretic process that the support medium be uniform and free from imperfections. For example, agarose has been found to be an excellent support medium. The agarose is formed into a gel layer into which the sample substance is placed. An electrical potential is maintained across the gel layer and the particle migrations take place. The gel layer is reacted with a chemical mixture to render the separation visible and readable by a trained individual. Different chemical mixtures may be employed to visualize different classes of separated substances as is known in the art.
A problem which has plagued electrophoretic analysis in the past has been the difficulty of production and maintenance during shipping of the gel layers. That is, due to their chemical composition, the gel layers are difficult to fabricate in situ and thus must be shipped and stored for use by laboratories. The shipping and storage is rendered difficult by the relatively fragile nature of the gel layers. Because the gel layers are very delicate, it is important that suitable protective containers be used. One such container is disclosed in U.S. Pat. No. 3,479,265 issued to F. R. Elevitch on Nov. 18, 1969. In that device, the container includes an upper portion and a lower portion. The lower portion is a flexible sheet which is adhesively attached to the upper portion to form a void space therebetween. The gel substance is injected into this void space and allowed to congeal. The gel is shipped in this container and, when it is desired to utilize the gel layer, the sheet with the gel layer adhering thereto is peeled away from the upper portion. While suited for its intended purpose, the gel layer may stick to the upper portion and is in constant contact with this upper portion during shipment and storage. Because of this contact, flaws, such as pock marks or cracks, may appear in the gel layer. These flaws are aggravated by shrinkage which is caused by dehydration of the gel layer. In addition, impurities contained on the upper portion contribute to the flaws by marring the surface of the gel layer.